1. Field of the Invention
The present invention relates to mapping a source identification used in associating electronic programming guide (EPG) content information with television signals.
2. Background Art
A cable television provider streams television signals from a headend controller to a number of settop boxes (STB) over cable lines or other mediums. Selective portions of the signals are acquired by the STB for viewing desired channels. As part of these signals, the STB receives a channel map for determining if a user-selectable channel is part of the channel map, and is hence, tunable. The channel map is typically downloaded to the STB from the headend controller. Part of this download includes a table or other arrangement for relating channels or call signs to a particular channel identification or source identification (ID).
In addition to displaying the selected channel, the STB may include an electronic programming guide (EPG) for displaying EPG content information associated with the available channels. The EPG content information provides textual and visual descriptions of programs, movies, news, or other items showing on a particular channel for a particular period in time. The EPG can provide a number of features for displaying the EPG content information, such as in a selection guide that displays content information for a number of channels according to a number of time slots and/or in an overlay that appears across the bottom of the screen when the tuned to channel is changed.
Most headend controllers use a vendor-specific approach for providing the mapping of channel numbers to source IDs. In this approach, the source ID for each channel is predefined by the EPG vendor as a numeric reference value for that content source, such as 10,001 for ESPN, 10,002 for HBO, etc. The source ID is used by the STB to correlate the channel number with EPG content on that channel. The EPG content information is provided to the STB by the EPG content vendor. Like the cable television provider, the EPG vendor streams EPG content signals to the STB over the cable lines or other communication medium. The EPG selects the desired EPG content information from the signals based on the source ID. In general, the STB receives a channel input from a user, consults the channel map to determine the channel's existence in the map and its associated source ID, tunes to the desired channel and puts up source-specific EPG content based on the source ID information.
A problem arises with this approach, however, if the cable television provider desires to change the EPG vendor to a new EPG vendor that associates its EPG content information with source IDs that are different from the source IDs of the original EPG vendor. The ability to change EPG content providers is desirable because some EPG vendors provide better services than others. To accommodate a new EPG vendor, the headend controller must either change the channel map(s) to reflect the new source IDs, or support duplicate channel maps, one with each set of EPG vendor-specific source IDs. Changing the channel map each time the EPG vendor is changed is undesirable because it can lead to long-term operational maintenance issues and/or cause interruptions in service. Supporting duplicate channels maps is undesirable because it consumes bandwidth and leads to long-term operation maintenance issues. Also, with each new EPG vendor, a new variant of the channel map would need to be created, making the solution even more untenable.